* thread_pthread.c (ubf_select): activate timer thread when interrupt
	  blocking thread.
	  A patch created by Koichi Sasada. [ruby-core:39634] [Bug #5343]
	  to cover race condition, timer thread periodically send SIGVTARLM to
	  threads in signal thread list. so you should activate timer thread
	  when interrupt a thread.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@33310 b2dd03c8-39d4-4d8f-98ff-823fe69b080e